Controlled growth factor delivery system with osteogenic-angiogenic coupling effect for bone regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Bone regeneration is a complex process regulated by growth factors like BMP-2, VEGF, and FGF-2.
• Optimizing the delivery of these factors is crucial for effective bone tissue engineering.

Purpose of the Study:

• To investigate the effects of dual release of BMP-2, VEGF, and FGF-2 on bone regeneration in femur defects.
• To evaluate a composite scaffold designed for controlled, dual release of these key growth factors.

Main Methods:

• A composite scaffold was fabricated using Gelatin microparticles (VEGF/FGF-2) and PLGA-PEG-COOH microparticles (BMP-2) within an nHA-PLGA structure.
• The release kinetics of BMP-2, VEGF, and FGF-2 were analyzed.
• Osteogenic differentiation of bone mesenchymal stem cells (BMSCs) and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) were assessed.
• Bone and blood vessel formation in femur defects were analyzed post-implantation using micro-CT and histology.

Main Results:

• Differential release rates of BMP-2 compared to VEGF and FGF-2 were observed over time.
• Controlled dual release of BMP-2, VEGF, and FGF-2 significantly induced osteogenic differentiation in BMSCs.
• The composite scaffold promoted VEGF expression in BMSCs, enhancing HUVEC proliferation and angiogenic differentiation.
• Significant new bone and blood vessel formation were observed in femur defects after 12 weeks.

Conclusions:

• Dual delivery of angiogenic and osteogenic factors via the composite scaffold creates an osteogenic-angiogenic coupling effect, enhancing bone regeneration.
• This approach offers insights into designing high-performance bioscaffolds for bone tissue engineering applications.